[已解决] 启动报错 Correct single, compatible version of XXX

项目结构：
Maven父子级工程
引入依赖：
子项目引入Euraka server
父项目引入spring-bootstarter等等

子工程Spring Boot项目启动失败，报如下错误：

***************************
APPLICATION FAILED TO START
***************************

Description:

An attempt was made to call a method that does not exist. The attempt was made from the following location:

    org.apache.catalina.authenticator.AuthenticatorBase.startInternal(AuthenticatorBase.java:1321)

The following method did not exist:

    javax.servlet.ServletContext.getVirtualServerName()Ljava/lang/String;

The method's class, javax.servlet.ServletContext, is available from the following locations:

    jar:file:/C:/Users/xxx/.m2/repository/javax/servlet/servlet-api/2.5/servlet-api-2.5.jar!/javax/servlet/ServletContext.class
 jar:file:/C:/Users/xxx/.m2/repository/org/apache/tomcat/embed/tomcat-embed-core/9.0.35/tomcat-embed-core-9.0.35.jar!/javax/servlet/ServletContext.class
It was loaded from the following location:
file:/C:/Users/XXX/.m2/repository/javax/servlet/servlet-api/2.5/servlet-api-2.5.jar
Action:

Correct the classpath of your application so that it contains a single, compatible version of javax.servlet.ServletContext

Process finished with exit code 0

重点在于最后这句： Correct the classpath of your application so that it contains a single, compatible version of javax.servlet.ServletContext

Maven Build时正常，说明是运行时import的包有冲突。 网上很多人的说法是找冲突的包，然后删掉重复即可。
但正常配置的项目不会有这样的问题，根本原因还是配置。

经查，发现我的问题是，子项目的pom.xml中没有配置正确的Spring Cloud版本。

错误的pom配置：👇直接将依赖的版本写到dependency中

<dependencies>
    <dependency>
        <groupId>org.springframework.cloud</groupId>
        <artifactId>spring-cloud-starter-netflix-eureka-server</artifactId>
        <version>2.2.2.RELEASE</version>
    </dependency>
</dependencies>

改为如下格式即可： 👇 指定spring cloud的version，由Spring cloud管理依赖的版本

<properties>
    <java.version>1.8</java.version>
    <spring-cloud.version>Hoxton.SR4</spring-cloud.version>
</properties>
<dependencies>
    <dependency>
        <groupId>org.springframework.cloud</groupId>
        <artifactId>spring-cloud-starter-netflix-eureka-server</artifactId>
    </dependency>
</dependencies>

<dependencyManagement>
    <dependencies>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-dependencies</artifactId>
            <version>${spring-cloud.version}</version>
            <type>pom</type>
            <scope>import</scope>
        </dependency>
    </dependencies>
</dependencyManagement>

重新build，运行，发现运行良好。